F I see it as such:
1. Johnson now (as usual) will start throwing money from the magic money tree at the Cost of Living Crisis to appease his MP's and garner support. This will include bringing forward the tax threshold rise, maybe a cut in fuel VAT and some other tax thing to benefit business. Non of this will change the public perception enough to boost his approval ratings.
2. The two by-elections will be lost. Pressure will mount.
3. He surely can't call a GE after 2 by-election defeats so he'll plod on until the Privileges Committee findings. If they find that he misled the house he'll resign, if not he'll carry on. If he doesn't resign the 1922 will change the rules and they will hold another confidence vote. He will then be kicked out. The new leader could well then call a GE.
That's the only way I see a GE being called. It would be suicide for the Tories to throw away their majority early going into a GE with Johnson as leader.
But despite what Johnson does there is nothing he can now do to significantly improve his popularity. He's played all his cards and it can only get worse for him. After all they have just backed Ukraine and spent £37b on Cost Of Living help and it has barely changed his polling. He's done.